M-S and M-O-S contacts to N-polar GaN on silicon (111) for UV photodetector application

Various (Au, Pt, Ir) M-S and M-O-S type contact to N-polar GaN layer on Si(111) via oxide buffers were fabricated and characterized. The influence of rapid thermal annealing processes on electrical properties and contact morphology was examined. Iridium based contacts, annealed in 700 °C, exhibit lowest dark current (Φ B = ~1.1 eV) and are thus identified as most suitable for UV photodetector applications.